The present invention relates to a conveyer system for conveying a carrier member which is carrying a workpiece among working stations.
Conventionally, a conveyer system for transferring carrier members such as hangers which hold a workpiece such as a sewing product in a sewing plant and the like has been known. For example, in a conveyor system endless main lines 66 are connected with a large number of sub-lines 65 each of which is provided with working stations such as sewing stations, each end of the main lines 66 being connected to a connection line 67 which is also formed to be endless, a carrier member which carries a workpiece being transferred from one sub-line 65 to another sub-line 65 along the main line 66 and the connection line 67 (refer to FIG. 1). (For example, see U.S. Pat. No. 3,592,141).
In the meantime, in many production fields including the sewing field, it is required that the layout of the conveyer system is flexibly modified or expanded in the plant because of the change of producing process. In addition, the carrier member is also required to be transferred to an objective station through the shortest route.
In the conventional structure described above, however, since the sub-lines 65 which are provided with working stations are connected with each other through the endless main line 66 and the connection line 67, the layout cannot be flexibly changed and expanded as desired.
As shown in FIG. 1, in the conventional conveyer system, each sub-line 65 is arranged in parallel around the main line 66, and each main line 66 is arranged in parallel around the connection line 67. Thus, the sub-lines 65, or the working stations cannot be flexibly networked. Moreover, as shown by two-dot lines in FIG. 1, when an another main line 66 which is provided with a plurality of sub-lines 65 is built, a very complicated work is required, that is, one end of the endless connection line 67 should be cut; new chains and rails should be additionally connected in order to stretch the entire system; and struts and fasteners which support the connection line 67 should be added.
In addition, during the construction period when the mainline 66 is expanded, for example, since the connection line 67 should be cut and inoperative, the entire operation of the conveyer system should be halted. To prevent that, conventionally, the facilities are built with estimating the future expansion, which results in losses of the investment, construction time period, and running cost.
Moreover, since each main line 66 and the connection line 67 always run in a single direction, two working stations on different two sub-lines 65 cannot be connected through the shortest route. Therefore, the hanger cannot be transferred to the objective working station in a short time.
In FIG. 1, for example, although the working station A on the sub-line 65 is close to the station B or the station C on the same sub-line 65, the hanger can not be directly transferred from the station A to the station B or the station C along the arrow D or E. Instead, as shown by the arrow F, the hanger should be conveyed through a roundabout way, thereby it takes relatively a long time.
Especially when the hanger is conveyed between working stations on different main lines 66, 66, such a problem is highlighted. For example, when the hanger is conveyed from the working station A on the sub-line 65 to a station G on the sub-line 65, it should be conveyed all the way along an arrow H, an arrow G, an arrow I, and an arrow J.